Duplicating machine



July 16, 1963 E. RUTISHAUSER DUPLICATING MACHINE Filed Sept. 4, 1959*Eagar 1 070 56 agsek /h (/60 for United States Patent Ofiice 3,097,599Patented July 16, 1963 3,097,599 DUPLICATIN G MACHINE EdgarRutisliauser, Todistrasse 1, Zurich, Switzerland Filed Sept. 4, 1959,Ser. No. 838,317

Claims priority, application Switzerland Sept. 10, 1958 3 Claims. (Cl.101-416) The present invention relates to duplicating machines, and moreparticularly to a duplicating machine of the rot-ary drum type equippedwith auxiliary devices actuated by compressed air.

An object of the invention is the provision of airactuated dust removalmeans for removing dust from the paper sheets and the like on which animprint is to be made.

Another object is to provide means for removing dust from the stencilfrom which the imprint is to be transferred to the sheet material.

An additional object is the provision of air-operated dusting means fordepositing a layer of powdery absorbent material on a printed sheet soas to prevent ink transfer from the sheet to another sheet superimposedon the printed surface when the sheets discharged from the machine arestacked.

A further object of the invention is to provide means for separatingindividual sheets on a feed stack of sheets from each other so as tofacilitate feeding of the sheet material.

Yet another object is the provision of means for assisting release of asheet from the stencil and the drum to which the sheet may adherebecause of mechanical adhesion or by attraction of opposite electriccharges on the stencil or drum and the sheet material.

With these and other objects in view, the invention provides an air pumpconstituting a source of air under positive pressure. Motiontransmitting means connect the air pump to one of the plurality ofmovable elements of a duplicating machine which move sheet materialthrough the machine along a predetermined path. The air pump is therebyactuated when said movable element moves. A conduit communicates withthe air pump, that is, the source of air under pressure, and with anozzle arranged along the path of movement of the sheet material fordischarging a stream of air against the sheet material.

According to an additional feature of the invention, there are providedseveral nozzles which may be connected to the source of air by aselector valve which permits the nozzles to be supplied with air eithersimultaneously or alternatively. One of the nozzles is preferablyarranged adjacent the duplicating machine drum and directs a stream ofair against the drum for removing dust from the stencil, and also forassisting in lifting a printed sheet from the stencil. Another nozzlemay be arranged at the feeding station for removing dust from thetopmost sheet as it is being fed from a stack of sheets towards thedrum. A third nozzle may be arranged at the discharge station whichreceives the printed sheets from the drum, and may be equipped with adusting device which deposits a layer of absorbent powder on the freshlyprinted sheet.

Other objects and features of this invention, and many of the attendantadvantages will be readily appreciated as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawing wherein:

FIG. 1 is a fragmentary perspective view of a duplicating machineequipped with a preferred embodiment of the invention.

Referring now to the drawing, there is shown the rotary drum 1 of aconventional rotary-drum type duplicating machine. The drum cooperateswith a pressure roller 2 in a well-known. manner. A stack 3 of blanksheets of paper is provided at a feeding station ahead of the drum inthe direction of movement of the sheet material through the machine. Theblank sheets are individually fed to the drum by a feed roller 4 mountedon a support bracket 4a for reciprocating movement indicated by thearrows h and r. The movement of the bracket 4a is actuated by a linkage(not shown) connecting the bracket to the drum or to a common manual orautomatic drive as is well-known. The drive causes the feed roll 4 tomove towards and away from the drum 1, and causes the drum to rotaterelative to the feed roll 4.

A lever 5 pivoted on the frame (not shown) of the duplicating machinehas one end pivotally secured to the support bracket 4a and another endattached to the piston rod of a piston 6 which is reciprocally guided ina cylinder 7. The cylinder is suitably fastened on the machine frame andforms an air pump with the piston 6. The pump is also equipped withcheck valves (not shown) 1 which may, for example, be arranged in thepiston 6 and in the discharge end of the cylinder 7 respectively topermit flow of air through the piston into the cylinder and from thecylinder through the conduit 9 only.

The conduit 9 connects the cylinder with an intake nipple 24 on thecylindrical sleeve 10* of a selector valve. A hollow valve plug 11 isslidably arranged in thes-leeve 14 One end of the plug extends outwardlyfrom the sleeve, and is shaped to form a handle by means of which thevalve may be opera-ted. The plug is formed with a radially and axiallyextending slot 25 which provides communication between the conduit 9 andthe central bore of the plug. A radial opening in the plug 1 1 oppositethe slot, designated 26, 27, and 2.8, respectively, can be selectivelyaligned with three discharge nipples 29, 30, and 31, respectively, ofthe control valve by axially sliding the valve as indicated by doublearrows. The radial openings 26, 27, and 28 form parts which arediametrically opposed to the slot 25. The plug may be secured in any oneof :the aligned positions by engagement of a spring biased pin 10a,which is radially 'slidable in the sleeve 1%), with three correspondingnotches 11a in the plug.

Communication between the conduit 9 and all three discharge nipplessimultaneously can be established by rotating the plug through from theillustrated posi tion so that the slot communicates with the threenipples and the single radial opening is aligned with the intake nippleon the valve sleeve.

A flexible tube 12 is connected to one of the discharge nipples on thevalve sleeve 10 to transmit air from the valve in the direction of thearrow to a perforated tube 16 arranged transversely of the path ofmovement of the paper sheets 15 from the feeding station to theduplicator drum 1. The tube 16 has several radial openings 17 which arearranged in such a manner as to direct streams of air over the surfaceof the sheet 15, and to blow off any dust which may have been depositedon the sheet. Removal of the dust is important for long runs from asingle stencil. Dust tends to be transferred from the sheet material tothe inked stencil and to blur the impressions made. Keeping the stencilfree from dust permits to run a greater number of clear prints.

As clearly seen from the drawing, a portion of the air streams emanatingfrom the openings 17 is directed against the facing cut edges of thesheets 15 on the stack 3' so as to separate the top sheets from eachother and to facilitate feeding of the topmost sheet to the drum 1 bythe feed roller 4.

The second discharge nipple on the sleeve 10 of the selector valve has aflexible tube 13- attached thereto. Air may flow from the valve in thedirection of the arrow through the tube 13 to a rigid tube 18 ofapproximately square cross section which is equipped with longitudinalrows of openings 19. Jets of air released through the openings aredirected against that portion of the surface of the drum 1 at which thesheet of paper is to be released from the stencil after the imprint hasbeen made. The leading edge of the paper sheet forms a very small,funnelshaped slot with the stencil face since the edge never completelyadheres to the stencil. The jets of air from the openings 19 aredirected into this slot and facilitate release of the paper from thestencil. At the same time, the air moving rapidly over the freshlyexposed stencil surface tends to carry away particles of dust which mayhave been deposited on the stencil and which may not yet be held verytenaciously by the stencil surface.

The third discharge nipple of the valve sleeve is connected with aflexible tube 14 leading air in the direction of the arrows through anupright hollow support 21 to a container in which an absorbent powderymaterial such as very finely ground chalk or the like is held. The airpassing through the container 20 in turbulent fiow causes a portion ofthe powdery material to be suspended in the air and to be entrainedthereby. The air with the powder suspended therein passes from thecontainer 20 into a discharge duct 22 which terminates in a nozzle 23arranged above the chute 8 which forms the discharge station of theduplicating machine. The nozzle distributes a fine layer of chalk andthe like on each freshly printed sheet as it is discharged from the drum1 with its printed face up. It will be understood that the sheets mayaccumulate in the chute 8 to form a stack similar to the stack 3, orthat they may continuously slide from the chute toward a point ofstorage.

The distribution of duplicator ink over the face of the printed sheetvaries according to the nature of the printed material. To permitadjustment of the size of the area dusted by the nozzle 23 withabsorbent powder, two obliquely downwardly extending portions of theduct 22 are arranged to telescope inside each other so that the verticalposition of the nozzle 23 can be adjusted. This changes the area coveredby the dusting powder. The discharge duct 22 is also rotatably connectedto the container 20 so that the nozzle 23 can be moved arcuately toconcentrate the discharged powdery material in any desired portion ofthe printed sheet discharged on the chute 8.

The device illustrated is arranged for manual control of the valve plug11 so that it may at any one time connect only one of the air operatedauxiliary devices to the air pump during the entire operating cycle orduring any portion thereof, or be reversed to connect all the devicessimultaneously for continuous operation during each power stroke of thepump. It will be understood though that the valve may be linked with themoving members of the duplicating machine in such a manner that thevalve sequentially opens and closes each discharge nipple once duringthe printing cycle. This may be accomplished, for example, by providingan axial extension member on the valve plug 11 which connects with thelever 5 in such a manner that the plug is axially reciprocated onceduring eah reciprocating movement of the feed roller 4.

The plug 11 may also be replaced by a rotary selector valve having asingle intake and several discharge nipples which are sequentiallyconnected with the intake nipple during each turn of the rotary valvemember. The rotary member may be mounted coaxially on the drum 1 or on ashaft carrying the drum so that each air-operated auxiliary device isactuated once during each turn of the drum. If it s desired to open theconduits leading to the auxiliary devices more than once during eachturn of the drum or during each reciprocating movement of the feedroller 4, this is readily accomplished by providing a plurality ofdischarge nipples on the valves each communicating with the same conduitleading to the device under consideration.

Instead of actuating the piston 6 by a lever 5 connected to the feedroller 4, the invention also contemplates connecting the piston to thedrum 1 by any device known to convert rotary movement into reciprocatingmovement. The air pump may be placed in such a manner that itreciprocates in a plane which is radial relative to the axis of the drum1 and the piston 6 may be driven by a connecting rod eccentricallysecured to the radial drum face.

While the single-acting piston pump 6, 7 has been found verysatisfactory for a duplicating machine of the type illustrated, acontinuous supply of air under pressure to the auxiliary devices of theinvention may be desirable. This may be obtained by making the air pumpdouble acting so that both strokes of the piston 6 are power strokes.The necessary arrangement of check valves and piping is too well knownto require any detailed discussion. It is also contemplated to replacethe piston pump illustrated by a rotary pump or a centrifugal pumpactuated by the drum 1 or the shaft of the drum 1 (not shown). Dependingon the desired volume and pressure of air, the pump may be mounted onthe machine frame and the rotary member connected to the drum 1 forjoint movement at equal or at higher speed, for example by a belt orgear transmission.

The piston pump 6, 7 which constitutes a source of air under pressuremay also be replaced by an electrically driven centrifugal pump withoutdeparting from the scope of this invention.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention, and that it isintended to cover all changes and modifications of the example of theinvention herein chosen for the purpose of the disclosure which do notconstitute departures from the spirit and scope of the invention setforth in the appended claims.

What is claimed and desired to be protected by Letters Patent of theUnited States is:

1. In a duplicating machine having a rotated drum adapted to carry astencil for marking successive sheets as the latter are fed by areciprocated sheet feeding member from a stack of the sheets at afeeding station along a path that includes a portion of the surface ofthe drum to a discharge station; the combination of air pumping meansoperative to supply air under pressure, mechanical linkage meansconnecting said sheet feeding member with said air pumping means foroperating the latter in response to reciprocation of the sheet feedingmember, selector valve means having an inlet connected with said airpumping means for receiving air under pressure from the latter and aplurality of outlets, said valve means being actuable to selectivelycommunicate said outlets with said inlet, first, second and third nozzlemeans located to direct streams of air against the successive sheets atsaid feeding station, at said portion of the surface of the drum and atsaid discharge station, respectively, conduit means connecting saidfirst, second and third nozzle means with respective outlets of saidselector valve means, and a container for powdery material interposed inthe conduit means between said valve means and said third nozzle meansso that air streaming from the latter entrains powdery material fromsaid container.

2. In a duplicating machine, the combination as in claim 1; wherein saidvalve means includes a cylindrical casing having said inlet at one sidethereof and said outlets spaced apart in the direction of thelongitudinal axis of the cylindrical casing at the opposite side of thelatter, and a hollow plug slidable axially and rotatable in said casing,said plug having an axially elongated slot and at least onediametrically opposed port, so that, when said plug is turned to alignsaid slot with said inlet of the casing, axial movement of said plugselectively registers said port with said outlets, and, when said plugis turned to align said port with said inlet, said slot simultaneouslyregisters with all of said outlets.

3. In a duplicating machine having a rotated drum adapted to carry astencil for marking successive sheets as the latter are fed by areciprocated sheet feeding member from a stack of the sheets at afeeding station along a path that includes a portion of the surface ofthe drum to a discharge station; the combination of air pumping meansoperative to supply air under pressure, mechanical linkage meansconnecting said sheet feeding member with said air pumping means foroperating the latter in response to reciprocation of the sheet feedingmember, selector valve means having an inlet connected with said airpumping means for receiving air under pressure from the latter and atleast two outlets, said valve means being actuable to selectivelycommunicate said outlets with said inlet, at least two nozzle meansarranged at spaced apart locations to direct streams of air against thesuccessive sheets as they move along said path, conduit means connectingeach of said nozzle means with a respective one of said outlets, and acontainer for powdery material interposed in said conduit means betweensaid valve means and one of said nozzle means so that air streaming fromsaid one nozzle means entrains powdery material from said container.

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1. IN A DUPLICATING MACHINE HAVING A ROTATED DRUM ADAPTED TO CARRY ASTENCIL FOR MARKING SUCCESSIVE SHEETS AS THE LATTER ARE FED BY ARECIPROCATED SHEET FEEDING MEMBER FROM A STACK OF THE SHEETS AT AFEEDING STATION ALONG A PATH THAT INCLUDES A PORTION OF THE SURFACE OFTHE DRUM TO A DISCHARGE STATION; THE COMBINATON OF AIR PUMPING MEANSOPERATIVE TO SUPPLY AIR UNDER PRESSURE, MECHANICAL LINKAGE MEANSCONNECTING SAID SHEET FEEDING MEMBER WITH SAID AIR PUMPING MEANS FOROPERATING THE LATTER IN RESPONSE TO RECIPROCATION OF THE SHEET FEEDINGMEMBER, SELECTOR VALVE MEANS HAVING AN INLET CONNECTED WITH SAID AIRPUMPING MEANS FOR RECEIVING AIR UNDER PRESSURE FROM THE LATTER AND APLURALITY OF OUTLETS, SAID VALVE MEANS BEING ACTUABLE TO SELECTIVELYCOMMUNICATE SAID OUTLETS WITH SAID INLET, FIRST, SECOND AND THIRD NOZZLEMEANS LOCATED TO DIRECT STREAMS OF AIR AGAINST THE SUCCESSIVE SHEETS ATSAID FEEDING STATION, AT SAID PORTION OF THE SURFACE OF THE DRUM AND ATSAID DISCHARGE STATION, RESPECTIVELY, CONDUIT MEANS CONNECTING SAIDFIRST, SECOND AND THIRD NOZZLE MEANS WITH RESPECTIVE OUTLETS OF SAIDSELECTOR VALVE MEANS, AND A CONTAINER FOR POWDERY MATERIAL INTERPOSED INTHE CONDUIT MEANS BETWEEN SAID VALVE MEANS AND SAID THIRD NOZZLE MEANSSO THAT AIR STREAMING FROM THE LATTER ENTRAINS POWDERY MATERIAL FROMSAID CONTAINER.